Ethyl alcohol has become an essential ingredient of organic cosmetics. Still some are worried that alcohol dries and irritates the skin. What's the reality?

Humans have known alcohol for thousands of years. It has been used for various purposes: preparation of drinks, medicine, household and manufacturing. Due to its antimicrobial qualities, alcohol has also become an essential ingredient in the production of organic cosmetics. And yet some are worried that alcohol dries and irritates the skin. What's the reality? A review of scientific publications on alcohol debunks the 5 most common misconceptions about alcohol effects on the skin.

CLARITY FIRST: WHAT IS ALCOHOL?

Natural plant ethyl alcohol, also called ethanol, food grade alcohol, pure alcohol or grain alcohol is a colourless, volatile liquid with a light scent. Food grade alcohol is produced from grain (wheat or rye), corn or sugarcane in the process of sugar fermentation.

The term alcohol is most commonly used when talking about ethyl alcohol or ethanol. In chemistry, however, alcohol is a large group of substances whose molecules contain the hydroxyl (OH) part. Ingredients like glycerine, menthol, many plant-derived waxes are also alcohols according to their chemical structure.   There are also many synthetically-derived alcohols. Certified natural cosmetics, however, can only contain natural ethyl alcohol, derived from plants. 

The majority of the scientific data about alcohol’s effects on the skin are available from the studies with high ethanol concentrations, for example, such as those used in hand disinfectants (50–97% ethanol). In fact, those studied high ethanol concentrations, up to ten times exceeding those used in cosmetic products. 

And now, to the myths.

1. Does alcohol dry out the skin? NO

People tend to associate alcohol in cosmetics with skin dryness. Although there are still conflicting data from scientific studies, experimental data show there is no transepidermal water loss after topical ethanol application. In fact, a scientific study that investigated the use of ethanol-based hand rubs and concluded that the use of alcohol for hand hygiene has clear advantages over washing with water and soap. Therefore alcohol-based hand hygiene is preferred from the dermatological point of view.

2. Does alcohol irritate the skin? NO

Various scientific and experimental studies show that skin-irritation of alcohol is insignificant. The irritant potential of alcohol in hand antiseptics is very low. There is a long history of dermal application of ethanol in the form of surgical spirit (7080% ethanol in water) with no concern for skin irritancy. A skin patch test study conducted with 100% ethanol showed no erythema on intact skin.

3. DOES ALCOHOL CAUSE ALLERGY? NO

If the skin is pre-irritated, alcohol can cause a burning sensation which, however, is not an allergic reaction and does not further harm the skin. True allergic reactions to alcohols have so far not been confirmed. 

4. DOES ALCOHOL ABSORB IN THE SKIN? NO

Scientific data prove that the dermal absorbtion of the ethanol is insignifficant. In a comparative human use study, where high ethanol concentrations were applied to skin, none of the blood samples, taken from sixteen human volunteers, exhibited a detectable level of alcohol. Skin absorption of ethanol is insignificant, primarily due to loss from the skin via evaporation. In addition, the molecule structure of ethanol contributes to the poor dermal uptake in human skin. Many high quality scientific studies on dermal penetration of alcohol have affirmed the safety of topically used ethanol.

5. DO ALCOHOL-CONTAINING PRODUCTS DAMAGE THE SKIN? NO

Unlike most other skin care product preservatives, alcohol evaporates from the skin surface in seconds. Alcohol contributes to the microbiological safety of the cosmetic product in the packaging, but once it is applied on the skin, it vanishes quickly – the half-life for the ethanol evaporation from skin is just 11.7 seconds. The majority of other anti-amicrobial agents are not highly volatile, leading to dermal absorption, accumulation an increasing risks of skin damage and reactions after prolonged use of the substance. Studies on oral and dermal (skin) toxicity of cosmetic preservatives show that concentrated natural alcohol is the most gentle on skin. Its toxicity is 10 times lower than that of butylparaben and 4 times lower than that of phenoxyethanol and several organic acids. Alcohol helps to stabilise the product, without compromising the safety.

THE VERDICT

Scientific publications show even high concentrations of alcohol (50–95% ethanol) do not cause skin dryness, allergy or irritation, and do not significantly penetrate the skin. There is no skin damage associated with regular application of alcohol on the skin. Alcohol concentrations used in natural skincare are many times lower, which suggests that alcohol in cosmetic products is safe for the skin. From dermatological point of view, alcohol is one of the mildest antimicrobial agents and ethanol-containing products are safe even for those with sensitive and dry skin. Higher concentration of alcohol may be beneficial for combinated and oily skin types, helping to cleanse the skin as well as regulate the function of sebaceous glands. In addition, alcohol acts as a penetration enhancer for many active ingredients, boosting the effectiveness of a skin care product.

Sources
Ahmed-Lecheheb D, Cunat L, Hartemann P, Hautemaniere A. Prospective observational study to assess hand skin condition after application of alcohol-based hand rub solutions. Am J Infect Control. 2012;40:160–164.

Kirschner, M.H., Lang, R.A., Breuer, B. et al. Langenbecks Arch Surg (2009) 394: 151. doi:10.1007/s00423-007-0237-7

Kramer A, Below H, Bieber N, Kampf G, Toma CD, Huebner NO, Assadian O. Quantity of ethanol absorption after excessive hand disinfection using three commercially available hand rubs is minimal and below toxic levels for humans. BMC Infect Dis. 2007 Oct 11;7:117.

Andrew Maier, Jerald L. Ovesen, Casey L. Allen, Raymond G. York, Bernard K. Gadagbui, Christopher R. Kirman, Torka Poet, Antonio Quiñones-Rivera, Safety assessment for ethanol-based topical antiseptic use by health care workers: Evaluation of developmental toxicity potential, Regulatory Toxicology and Pharmacology, Volume 73, Issue 1, October 2015, Pages 248-264, ISSN 0273-2300, http://dx.doi.org/10.1016/j.yrtph.2015.07.015.

Pendlington R.U. (2001). Fate of ethanol topically applied to the skin. Food Chem. Toxicol., 39, 169-174.